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clean up divshiftcalc

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David Harris 2022-09-20 03:08:25 -07:00
parent 712f1d8d3a
commit 010c88816b
1 changed files with 9 additions and 6 deletions
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15
pipelined/src/fpu/divshiftcalc.sv
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@ -10,7 +10,9 @@ module divshiftcalc(
output logic DivResDenorm, output logic DivResDenorm,
output logic [`NE+1:0] DivDenormShift output logic [`NE+1:0] DivDenormShift
); );
logic [`NE+1:0] NormShift; logic [`LOGNORMSHIFTSZ-1:0] NormShift, DivDenormShiftAmt;
//logic [`NE+1:0] DivDenormShift;
logic DivDenormShiftPos;
logic [`DURLEN-1:0] DivEarlyTermShift = 0; logic [`DURLEN-1:0] DivEarlyTermShift = 0;
@ -25,6 +27,8 @@ module divshiftcalc(
// .0000xxxxxxxxxxx... >> 1 Exp = 1 // .0000xxxxxxxxxxx... >> 1 Exp = 1
// Left shift amount = DivQe+NF+1-1 // Left shift amount = DivQe+NF+1-1
assign DivDenormShift = (`NE+2)'(`NF)+DivQe; assign DivDenormShift = (`NE+2)'(`NF)+DivQe;
assign DivDenormShiftPos = ~DivDenormShift[`NE+1];
// if the result is normalized // if the result is normalized
// 00000000x.xxxxxx... Exp = DivQe // 00000000x.xxxxxx... Exp = DivQe
// .00000000xxxxxxx... >> NF+1 Exp = DivQe+NF+1 // .00000000xxxxxxx... >> NF+1 Exp = DivQe+NF+1
@ -33,12 +37,11 @@ module divshiftcalc(
// 00000000xx.xxxxx... << 1? Exp = DivQe-1 (determined after) // 00000000xx.xxxxx... << 1? Exp = DivQe-1 (determined after)
// inital Left shift amount = NF // inital Left shift amount = NF
// shift one more if the it's a minimally redundent radix 4 - one entire cycle needed for integer bit // shift one more if the it's a minimally redundent radix 4 - one entire cycle needed for integer bit
assign NormShift = (`NE+2)'(`NF); assign NormShift = (`LOGNORMSHIFTSZ)'(`NF);
// if the shift amount is negitive then dont shift (keep sticky bit) // if the shift amount is negitive then don't shift (keep sticky bit)
// need to multiply the early termination shift by LOGR*DIVCOPIES = left shift of log2(LOGR*DIVCOPIES) // need to multiply the early termination shift by LOGR*DIVCOPIES = left shift of log2(LOGR*DIVCOPIES)
assign DivShiftAmt = (DivResDenorm ? DivDenormShift[`LOGNORMSHIFTSZ-1:0]&{`LOGNORMSHIFTSZ{~DivDenormShift[`NE+1]}} : NormShift[`LOGNORMSHIFTSZ-1:0])+{{`LOGNORMSHIFTSZ-`DURLEN-$clog2(`LOGR*`DIVCOPIES){1'b0}}, assign DivDenormShiftAmt = DivDenormShift[`LOGNORMSHIFTSZ-1:0]&{`LOGNORMSHIFTSZ{DivDenormShiftPos}};
DivEarlyTermShift&{`DURLEN{~(DivDenormShift[`NE+1]|Sqrt)}}, {$clog2(`LOGR*`DIVCOPIES){1'b0}}}; assign DivShiftAmt = DivResDenorm ? DivDenormShiftAmt : NormShift;
assign DivShiftIn = {{`NF{1'b0}}, DivQm, {`NORMSHIFTSZ-`DIVb+1+(`RADIX/4)-`NF{1'b0}}}; assign DivShiftIn = {{`NF{1'b0}}, DivQm, {`NORMSHIFTSZ-`DIVb+1+(`RADIX/4)-`NF{1'b0}}};
endmodule endmodule